Dermal and transdermal systems and the technology thereof are conventionally well known and include therapeutic devices that have been designed to be applied on and held by typically an adhesive band directly to and in contact with the skin in desired or needed places or areas of typically the human body. Each patch of such systems holds or is the vector for holding one or more drugs that is/are designed to exert an action after release onto the skin and/or penetration through the skin covered by such patch(es). Typically composition or preparation applied to or embodied in a transdermal patch is composed of liquid, semi-solid or solid preparation in which drug(s) is/are dispersed, embodied and/or dissolved at a defined predetermined concentration, usually being in a high concentration. The patch(es) or membrane(s) is/are designed (engineered) to release drug according to a defined rate pattern--conventionally referred to as release rate. Alternately, a device such as the above-described cell type patch holder, typically includes a drug-containable patch-reservoir (container) having drug(s) placed therein and covered (restrained therein) by a particular especially selected or prepared membrane characterized with predetermined permeability to passage of the drug(s) when placed in contact with the skin. In any of such typical types of transdermal patches, the profile of release rate of the drug(s) must be determined accurately and reliably by use of a transdermal patch holder by which the patch may be subjected to drug relase by a leachable liquid. Use of the above-described nut and bolt type cell has proven to be cumbersome in use, as well as excessively time consuming in the matching of the bolt-receivable holes with the bolts, and thereafter screwing-on typically four separate nuts of four separate bolts. Another problem with the above-described nut-bolt cell arises from the annular reservoir being susceptable to failure to seat stably and securely the mounting edges of a reservoir-membrane type patch, which could lead to erroneous, faulty and/or inconsistent results in the leaching of the drug. Another problem arising from this particular prior art arrangement, is that the height of the unit results in the patch utilized sitting deeply in the holder thereby preventing maximum exposures to the movement of the leaching liquid or solution.
Prior to the present invention, in the technology of profiling of transdermal drug delivery systems represented by different types of transermal patches, there have existed problems associated with securing consistent and reliable determinations of release rate(s) thereof, such as above-described problems in the preceding paragraph. Additionally heretofore, mechanisms for supporting such transdermal patches have been cumbersome and bulky, requiring additional preparations such as adhesives and most importantly not having been standardized in regard to circumference and/or positioning within the leaching-vessel, for example. Another problem present has been the difficulty heretofore to unhindered exposure of drug-containing reservoirs to a body of leaching liquid. The art of measuring the amount of drug released in various types of leaching liquids for different types of drugs, is well known conventional prior art, and is not the subject matter of this invention. However, proper exposure of active surfaces and/or standardization of the holders are very important to properly ascertain reliably the true in-vitro rate of drug-release, and heretofore the prior apparatuses have not been optimal.